THE USE OF A SPECIFIC DNA PROBE AND POLYMERASE CHAIN-REACTION FOR THE DETECTION OF MYCOBACTERIUM-LEPRAE

A DNA probe encoding ∼80% of the 18-kDa protein gene of Mycobacterium leprae was isolated and tested for specificity by assessing hybridization of the probe to genomic DNA from taxonomically related and unrelated DNA samples. The 360-base-pair (bp) probe was specific for M. lepraeDNA and did not hybridize with genomic DNA from 18 species of bacteria nor with DNA from human, murine, and armadillo sources. Oligonucleotide primers were synthesized corresponding to the 5' and 3' ends of the 360-bp fragment to yield a fragment of similar size on amplification ofM. lepraeDNA by the polymerase chain reaction (PCR). Asimple procedure for DNA extraction from M. leprae-infected tissues was developed that provided suitable template DNA for amplification. The peR test was specific for M. leprae DNA from human and murine sources and detected M. leprae DNA in biopsies from leprosy patients and from control and uninfected human skin biopsy preparations seeded with as few as 100 M. leprae. © 1990 by The University of Chicago.